U.S. Patent No. 7,301,455 - Self-Configuring Emergency Event Alarm Network (Nov. 27, 2007)

The present self-configuring emergency event alarm network uses a decentralized (ad hoc or mesh) architecture that does not have a centralized "master" node. In this ad hoc network, any node is capable of behaving as if it were the "master node" by autonomously reporting the alarm event directly to all other nodes in the ad hoc network independent of where the alarm event occurred. The network of alarm devices, therefore, can spread the alarm indication to the entirety of the area covered by the network of alarm devices and can also differentiate between a general alarm indication and the locus of the alarm event.